WeX Posted January 31, 2014 Share Posted January 31, 2014 Wow - another SF cycling special. This forum is becoming a parody of itself when it comes to these silly threads. I best leave the bike at home, I don't want to cause a massive pile up with my lights No one is moaning though, most are but having a conversation about the title of the thread. Maybe you could contribute to the discussion. Link to comment Share on other sites More sharing options...
TimmyR Posted January 31, 2014 Share Posted January 31, 2014 If fingers are to be pointed to the worst dazzlers on the road, I would probably go for people with all the spotlights, side lights, head lights and whatever, they tend to be on the big t****y range rovers or BMWs. Why are they doing it? To be dominant and agressive, why is a cyclist doing it? to be safe. Link to comment Share on other sites More sharing options...
Agent Orange Posted January 31, 2014 Share Posted January 31, 2014 No one is moaning though, most are but having a conversation about the title of the thread. Maybe you could contribute to the discussion. I never said anyone was moaning. I was making a point of how absurd this issue and some of the responses it has attracted is. As for the topic, as I cyclist I have a flashing red LED light on the rear of my bike and two flashing LED lights at the front. One on my bike and the other on my helmet. I cannot see how these could possibly cause a motorist a blinding distraction. I drive also and have driven past cyclists with multiple lights and they have never bothered me, let alone caused a hazard. Link to comment Share on other sites More sharing options...
RootsBooster Posted January 31, 2014 Share Posted January 31, 2014 You're asking how so? Well, get a light that flashes, and get someone to spin it round, fast, you will see dotted lines.... A bike light won't be spinning though Now, imagine seeing that, travelling towards you... or from one side to the other... it's a proven fact that ONLY flashing lights makes it more difficult to judge the speed and distance of the object.. Emergency vehicles have sirens, static lights, and lots of other stuff also, so not ONLY flashing lights... It's to do with the time between flashes... if it's a long time between flashes, you'll see it in point A, and next time you see the light, it'll be at point C or even D, so for that moment in between flashes, the bike, and rider effectively are invisible at night.... Think about it logically for a moment... and a quick Google search will show all the other threads and articles about this issue (lights, and flashing etc) but the fact they make it harder to judge speed and distance, is simple logic... That might be so for a slow flashing light, or a light moving between two (far apart) points rapidly, but the slowest a bike light is permitted to flash is 60 flashes per minute, with most flashing faster than that. The light would have to move extremely fast between two points for that flash rate to make it it difficult to judge the distance/speed of the cyclist. If the light were on the cyclist's helmet this rapid movement would cause dizziness or injury. If the light were on the handlebars this rapid movement would make it difficult to cycle. Link to comment Share on other sites More sharing options...
JFKvsNixon Posted January 31, 2014 Share Posted January 31, 2014 No one is moaning though, most are but having a conversation about the title of the thread. Maybe you could contribute to the discussion. Lets not beat around the bush though. Cyclists wind car drivers up because they don't have to spend what seems half their life stuck in traffic jams. The various rants on here are only a smoke screen for the anger they feel for cyclists not waiting their turn in traffic queues. Link to comment Share on other sites More sharing options...
RootsBooster Posted January 31, 2014 Share Posted January 31, 2014 I never said anyone was moaning. I was making a point of how absurd this issue and some of the responses it has attracted is. As for the topic, as I cyclist I have a flashing red LED light on the rear of my bike and two flashing LED lights at the front. One on my bike and the other on my helmet. I cannot see how these could possibly cause a motorist a blinding distraction. I drive also and have driven past cyclists with multiple lights and they have never bothered me, let alone caused a hazard. The only time I've ever been dazzled by bike lights is by off-road lamps (intended to light the path in front of you) which have been directed straight forward instead of down. I wonder if anyone was distracted by flashing Christmas LED's on houses last year? Some of those are ultra bright Link to comment Share on other sites More sharing options...
Claire_ Posted January 31, 2014 Author Share Posted January 31, 2014 Wow - another SF cycling special. This forum is becoming a parody of itself when it comes to these silly threads. I best leave the bike at home, I don't want to cause a massive pile up with my lights Wow. Another immature reply Link to comment Share on other sites More sharing options...
Cyclone Posted January 31, 2014 Share Posted January 31, 2014 Here you go. http://www.uctc.net/papers/667.pdf jb Doesn't address distance at all, and states that higher flash rates cause observers to over estimate speed. I can't see how this would be a problem to be honest. Drivers often seem to under estimate cycle speed and pull out when they shouldn't, so perceiving the bike as going faster than it actually is will just make them more cautious. Link to comment Share on other sites More sharing options...
monkey69 Posted January 31, 2014 Share Posted January 31, 2014 if you have never been on the road on a bicycle in bad/dark conditions then you cannot know how vulnerable you are to other road users. if you can offset this by displaying lights/florescent belts, jackets, capes then at least you are doing all you can to keep everyone safe. (except not riding the bike at all) some people would love that i bet!! Link to comment Share on other sites More sharing options...
barleycorn Posted January 31, 2014 Share Posted January 31, 2014 From the summary:Studies of the apparent translational speed of a flashing light moving along a straight path have shown that its translational speed tends to be overestimated if the flash (or flicker) rate is high. A flicker rate of 2 Hz serves to capture an observer’s attention without having a significant effect on perception of the light’s translational speed. We recommend, thus, that portable lights mounted on armbands or bicycle frames be set to flicker at 2 Hz and not more rapidly. So it's not the fact that a light flickers that is the problem but the speed it flickers at. ... the slowest a bike light is permitted to flash is 60 flashes per minute, with most flashing faster than that. So all we need now to decide the issue is the typical frequency at which bike lights flash. We have a minimum of 1Hz, what is the maximum available? jb Link to comment Share on other sites More sharing options...
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